The invention relates generaly to marine propulsion devices and, more particularly, to outboard motors including propulsion units which are steerable in a horizontal plane and tiltable in a vertical plane.
The invention also relates to hydraulic systems for power tilting of propulsion units between a lower normal running position in which the propeller is submerged in water, and a tilted or raised position in which the propeller is located for above-the-water-accessibility. Still more particularly, the invention relates to let-down of the propulsion unit after the striking of an underwater obstacle.
Various arrangements for power tilting and/or trimming of marine propulsion units are set forth in the following U.S. patents:
______________________________________ Carpenter 3,722,455 March 27, 1973 Shimanckas 3,847,108 November 12, 1974 Borst 3,863,592 February 4, 1975 Borst 3,885,517 May 27, 1975 Hall 3,983,835 October 5, 1976 Hall 4,064,824 December 27, 1977 Hall 4,096,820 June 27, 1978 Pichl 4,177,747 December 11, 1979 ______________________________________